merge

问题 I have a list of many data.frames that I want to merge. The issue here is that each data.frame differs in terms of the number of rows and columns, but they all share the key variables (which I've called "var1" and "var2" in the code below). If the data.frames were identical in terms of columns, I could merely rbind , for which plyr's rbind.fill would do the job, but that's not the case with these data. Because the merge command only works on 2 data.frames, I turned to the Internet for ideas.

问题 It's the first time I'm using stackoverflow and I don't speak English perfectly so be nice please. I'm using Jaxb in append mode like that for (Document330 document : documents){ JAXBContext jContext = JAXBContext.newInstance(Document330Xml.class); Marshaller m = jContext.createMarshaller(); m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE); m.marshal(document, fos); } And I have an output file like that: <?xml version="1.0" encoding="UTF-8" standalone="yes"?> <DOCUMENT> <MAILING>

问题 I have two dataframes: >>> df1 [Output]: col1 col2 col3 col4 a abc 10 str1 b abc 20 str2 c def 20 str2 d abc 30 str2 >>> df2 [Output]: col1 col2 col3 col5 col6 d abc 30 str6 47 b abc 20 str5 66 c def 20 str7 53 a abc 10 str5 21 Below is what I want to generate: >>> df_merged [Output]: col1 col2 col5 a abc str5 b abc str5 c def str7 d abc str6 I don't want to generate more than 4 rows and that is usually what happens when I try to merge the dataframes. Thanks for the tips! 回答1: Use .merge by

问题 using (StreamWriter writer = File.CreateText(FinishedFile)) { int lineNum = 0; while (lineNum < FilesLineCount.Min()) { for (int i = 0; i <= FilesToMerge.Count() - 1; i++) { if (i != FilesToMerge.Count() - 1) { var CurrentFile = File.ReadLines(FilesToMerge[i]).Skip(lineNum).Take(1); string CurrentLine = string.Join("", CurrentFile); writer.Write(CurrentLine + ","); } else { var CurrentFile = File.ReadLines(FilesToMerge[i]).Skip(lineNum).Take(1); string CurrentLine = string.Join("",

问题 using (StreamWriter writer = File.CreateText(FinishedFile)) { int lineNum = 0; while (lineNum < FilesLineCount.Min()) { for (int i = 0; i <= FilesToMerge.Count() - 1; i++) { if (i != FilesToMerge.Count() - 1) { var CurrentFile = File.ReadLines(FilesToMerge[i]).Skip(lineNum).Take(1); string CurrentLine = string.Join("", CurrentFile); writer.Write(CurrentLine + ","); } else { var CurrentFile = File.ReadLines(FilesToMerge[i]).Skip(lineNum).Take(1); string CurrentLine = string.Join("",

问题 I have a dataframe storing a date, car_brand, color and a city: date car_brand color city "2020-01-01" porsche red paris "2020-01-02" prosche red paris "2020-01-03" porsche red london "2020-01-04" porsche red paris "2020-01-05" porsche red london "2020-01-01" audi blue munich "2020-01-02" audi red munich "2020-01-03" audi red london "2020-01-04" audi red london "2020-01-05" audi red london I now want to create from that a dataframe in the following way: Merge rows together where for

问题 I need to merge a lot small csv-files from different source into separate bigger csv-files Usually I use: for /r E:\MyFolder %%d in (.) do ( copy "%%d\*.csv" "%%d\merge.txt" /B ) This works fine, but for a certain type of csv file, where a new line at the end missing where this won't work correctly. I can use : for %%x in (E:\MyFolder\case1\*.csv) do more "%%x" >>E:\MyFolder\case1\merge.txt But it won't run recursively, only for the top folder, obviously. I tried wrapping the same for loop as

问题 I need to merge a lot small csv-files from different source into separate bigger csv-files Usually I use: for /r E:\MyFolder %%d in (.) do ( copy "%%d\*.csv" "%%d\merge.txt" /B ) This works fine, but for a certain type of csv file, where a new line at the end missing where this won't work correctly. I can use : for %%x in (E:\MyFolder\case1\*.csv) do more "%%x" >>E:\MyFolder\case1\merge.txt But it won't run recursively, only for the top folder, obviously. I tried wrapping the same for loop as

问题 I need to merge a lot small csv-files from different source into separate bigger csv-files Usually I use: for /r E:\MyFolder %%d in (.) do ( copy "%%d\*.csv" "%%d\merge.txt" /B ) This works fine, but for a certain type of csv file, where a new line at the end missing where this won't work correctly. I can use : for %%x in (E:\MyFolder\case1\*.csv) do more "%%x" >>E:\MyFolder\case1\merge.txt But it won't run recursively, only for the top folder, obviously. I tried wrapping the same for loop as

问题 I need to merge a lot small csv-files from different source into separate bigger csv-files Usually I use: for /r E:\MyFolder %%d in (.) do ( copy "%%d\*.csv" "%%d\merge.txt" /B ) This works fine, but for a certain type of csv file, where a new line at the end missing where this won't work correctly. I can use : for %%x in (E:\MyFolder\case1\*.csv) do more "%%x" >>E:\MyFolder\case1\merge.txt But it won't run recursively, only for the top folder, obviously. I tried wrapping the same for loop as